The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

Of the many chalices in the running for the Holy Grail, this one in Valencia Cathedral sure looks the part.

This amazing example of Valencian Art Nouveau looks more like a cathedral than a public market.

Böttcherstraße's bells, extolling Nordic virtues and the great conquerors of the world.

The world's first zoo for microbes collecting the horrible and wonderful things living on and around us.

The ruins of the largest gladiatorial school in Rome are largely hidden under modern streets.

This hydrochronometer was invented by a Dominican monk and is a prime feature in this garden.

Romans decided this 16th-century "talking statue" was so ugly, they named it after a primate.

The spot where the fascist dictator made some of his most famous speeches including declaring war on Britain and France.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

The remains of this 2nd-century Roman temple are incorporated into a modern building.

A massive marble foot is tucked away in a small alley near the Pantheon.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

Breathtaking and huge 430 year old maps of Italy.

This Slovakian statue of an emerging sewer worker might just be a bronze peeping tom.

Also known as the Blue Church, the building was consecrated to the daughter of Andrew II.

Thousands of slain Soviet soldiers are buried within the shadow of this enormous obelisk.

This Polish cave has housed a dragon, a brothel, and an enduring legend.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

This century-old cinema house has a marquee that has been hand painted by a single man for over 25 years.

Among the ostentatious rococo ornamentation of this church, an image of death cuts the life-thread.

Go surfing on this urban wave, "hacked" by local surfers.